EXCSAT command (X'1041')
The distributed data management (DDM) architecture EXCSAT command initiates the exchange of attributes between a source application server and an IMS target server to identify the server class names and levels of DDM support of each server. The EXCSAT command must always be the first command sent from a source server to the IMS target server.
Format
Parameters
- DSSHDR
- The 6-byte header that contains information about the data stream structure (DSS).
- LL
- The length specified as a 2-byte binary integer. This length includes LL and CP.
- CP
- X'1041', the 2-byte codepoint of the EXCSAT command.
- EXTNAM
- Optional. The variable-length name of the process or thread that is requesting access to an IMS database. The specified name identifies the application thread for tracing and problem determination. If the job name includes embedded blanks, the name must be enclosed in quotation marks. The maximum length of EXTNAM is 255 bytes. The codepoint is X'115E'.
- SRVNAM
- Optional. The variable-length name of the source DDM server. The specified name identifies for tracing and problem determination purposes the hostname of the computer that the source application program is running on. If the server name includes embedded blanks, the name must be enclosed in quotation marks. The maximum length is 255 bytes. The codepoint is X'116D'.
- SRVCLSNM
- Specifies the DDM server class name used by IMS: DFS. DFS is currently the only class name supported by IMS. The SRVCLSNM enables the DRDA product-unique extension used by IMS.
Usage
The EXCSAT DDM command is used to initiate a request to access an IMS database and identify the requestor, a DDM source server to the DDM target server of IMS.
During the initial handshaking between the source and target DRDA servers, the source server must issue the EXCSAT command chained to the ACCSEC command.
In a successful exchange, the IMS target server returns the EXCSATRD reply data object in response to the EXCSAT command. The EXCSATRD reply object identifies the IMS target server to the source server.
Chained command objects
No command objects are chained to the EXCSAT command.
Reply data objects
In response to the EXCSAT command, the IMS target DDM server can return to the source DDM server the following reply data objects:
- EXCSATRD (X'1443')
- Exchange server attributes.
Error reply messages
In response to the EXCSAT command, the IMS target DDM server can return to the source DDM server the following error reply messages:
| Codepoint of reply message | Name of reply message | Meaning of reply message |
|---|---|---|
| X'1210' | MGRLVLRM | Manager-level conflict |
| X'124C' | SYNTAXRM | Data stream syntax error |
| X'1250' | CMDNSPRM | Command not supported |
| X'1251' | PRMNSPRM | Parameter not supported |
| X'1252' | VALNSPRM | Parameter value not supported |
| X'1254' | CMDCHKRM | Command check reply message |
| X'125F' | TRGNSPRM | Target not supported |